We conducted a comprehensive analysis of transcription of two candidate histone methyltransferases in human and mouse tissues, revealing tissue-specific expression of alternatively spliced and read-through transcripts. A major fraction of read-through transcripts may add an encoded protein domain modifying specificity of one the candidates. A manuscript is in preparation on this work. We conducted several yeast two-hybrid screens to identify protein-binding partners for the putative histone methyltransferases. These screens yielded several intriguing candidates that are being characterized further by biochemical and genetic methods in mammalian cells and in vitro. We have generated a conditional knockout mouse model lacking one of the putative histone methyltransferases located on a frequently deleted chromosomal region. The knockout mice could comprise a new model for chronic lymphocytic leukemia, for asthma, and/or for other cancers or human diseases.